Crusher for grinding-mills



(No Model") T. ROBERTS.

GRUSHBR FOR GRINDING MILLS.

No. 409,869. Patented Aug. 27, 1889.

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UNITED STATES PATENT OFFICE.

THOMAS ROBERTS, OF SPRINGFIELD, OHIO.

CRUSHER FOR GRINDING-MILLS.

SPECIFICATION forming part of Letters Patent N0. 409,869, dated August27, 1889. Application filed February 1, 1888. Serial No. 262,625. (Nomodel.)

To aZZ whom it may concern.-

Be it known that I, THOMAS ROBERTS, a citizen of the United States,residing at Springfield, in the countyof Clark and State of Ohio, haveinvented certain new and useful Improvements in- Crushers forGrinding-Mills; and I do declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to the letters and figuresof reference marked thereon, which form a part of this specification.

My invention relates to crushing and grind ing mills; and it consists inthe improvements hereinafter set forth in the specification, and moreparticularly pointed out in the claims. I

In my improvement I use two crushers, placed one over the other, mountedupon parallel or substantially-parallel shafts and geared to run atunequal rates of speed. These crushers may be constructed withcontinuous spiral crushing-flanges, or with lugs set so as to convey thematerial crushed toward one end of the case. These crushers areseparated by a plate which can be either fiXed or movable.

To accomplish the object of my invention more perfectly, the crushersare made to rotate in opposite directions, so that the material crushedmay be first conveyed by the upper crusher toward the end of the caseopposite the grinding devices and by the lower crusher toward thelatter, the plate between the two crushers having a discharge-hole at ornear the end opposite the grinding devices. The crushed material thustravels twice the length of the machine before reaching the b urrs. Theside wall toward which the crusher moves and the bottom plate of theupper compartment form resisting-surfaces and approximate closely enoughto crush the material coarsely before it enters the lower part of thecase.

Figure 1 is a vertical longitudinal sectionof a crushing and grindingmill embodying my improvement. Fig. 2 is a cross-section through line 12.

The arrows seen in both figures indicate the direction of rotation ofthe crushers.

A is the upper portion of the case, which is made in hopper form, withits two opposite sides a a inclined inward and downward, as seen in Fig.2, the upper crusher O being mounted on a horizontal shaft 0, journaledin bearings Z) I) at either end of the upper casesection A. The lowerportion of the case A differs from the upper one in form, it beingcylindrical in order to better conform to the operation of the lowercrusher O, which is also mounted on a horizontal shaft c,parallel withthe shaft 0 of the upper crusher O. \Vhen the crusher is connected withgrinding devices, as represented in Fig. 1, the runningburr B is alsomounted upon the same shaft 0' with the lower crusher.

The crusher-case is shown in two parts, bolted together through theprojecting horizontal flanges (Z (Z. It may, however, be made in onepiece, with a fixed or separable divisionplate between the crushers. Inthe views shown the two crushers are separated bya division-plateb,having ahole g therein,through which the crushed material from the uppersection A of the case is discharged into the lower section A. This plateor partition may be cast on one or the other sections, or it may beseparate and fitted between them.

In the views represented plate h is cast in one piece with the lowersection A.

It will be noticed that the lower crusher extending into the burr-caseleaves a space or opening at the opposite end under hole g, into whichthe crushed material from A may fall into the lower section A of thecase, and from thence be carried forward to the grinding devices bycrusher O. Two gear-Wheels h and h, connecting the shafts c and c, (onthe right in Fig. 1,) give the requisite variable speed to the crushersO and O. burr-shaft 0 requires a much higher velocity than the shaft 0of the upper crusher, the driving-pinion h is placed on the shaft 0'.The proportions of the two gear-wheels may be three or four to one or ofany rate desired, according to the kind of material to be operated.upon.

In operating the crushers, the corn or other material is placed in thehopper or upper section A of the case, and is broken by the crusher 0between its ribs e e and the side As the walls a a, after which it isdischarged through the hole 9 into section A, and is further reduced bythe crusher G. Directly in the Same Vertical plane with the shaft 0 inthe bottom of case-section A are two deep grooves i 1', extending thewhole length of the latter. These grooves are planed out or they may becast in the case, as preferred. This section of the case is purposelymade of greater thickness than the upper one to admit of these groovesbeing formed therein. The angles at the top of the side walls of thegroovest' i operate in connection with the crusher C to crush and breakup the material to the requisite fineness during its passage throughcase-section A to the burrs. One or more ribs have heretofore been formed upon the inner wall of the crusher-case for this purpose; but asthese ribs project from the wall they frequently become a source ofdanger in causing the crusher to become choked during its operation.,This is especially so when crushing corn in a moist or wet state. As noportion projects from the inner wall of the case A ,all liability tochoke is avoided. The crusher O is pivoted slightly below the axial lineof the case-section A to facilitate the operation of reducing thematerial between its ribs 6 e and the angles 2" 11' of the grooves i.

I do not claim the form of crushers herein shown, nor do I desire toclaim any particular form of crusher.

I claim as my invention 1. In a grinding-mill, acase formed with twocompartments, situated one above the other, and oppositely-rotatingcrushers in said compartments, the lower of which crushers is sosituatedas to leave a space between its end and the end of said case, incombination with a plate between said crushers serving to divide thecase into its compartments, and having a discharge-opening in its endimmediately above the space at the end of the lower crusher.

2. The combination, with a case having two compartments, situated oneabove the other, of a grinding or crushing roller in each of saidcompartments, the lower of which rollers has its ends located out oftransverse vertical alignment with the ends of the upper roller, asshown, whereby one end of said lower roller will be in contact wit-h ornear to one end of the case, and its opposite end will be suflicientlyfar away from the other end of the case to leave a space beneath thecorresponding end of the upper roller, and aplate between said rollerserving to divide the case into its compartments and formed with anopening above the space located at the end of the lower roller.

3. The combination, with a case having two compartments, situated oneabove the other, and a burr located at the end of the same and mountedupon a shaft passing through the lower compartment, of a grinding orcrushing roller in each of said compartments running in oppositedirections, the lower of which rollers is mounted upon the same shaft assaid burr and has its ends located out of transverse vertical alignmentwith the ends of the upper roller, so as to have one end eX- tend nearlyinto contact with the burr, and its opposite end sufficiently far awayfrom the end of the case to leave a space beneath the corresponding endof the upper roller, and a plate between the rollers serving to dividethe case into its compartments and formed with an opening above thespace beneath the end of the upper roller, for the purpose set forth. 4.The combination of a case having two compartments, situated one abovethe other, and formed on the bottom of the lower compartment withgrooves or mortises, and a burr located at the end of said case andmounted on a shaft extending longitudinally through said lowercompartment, and oppositely-rotatin g differently-speeded crushing-conveyers in said compartments, the lower of which is mounted on thesame shaft as said burr and has its ends located out of transversevertical alignment with the ends of the upper crushing-conveyor, and aplate serving to divide the case into its compartments and having adischarge-opening in its end immediately above the space at the end ofthe lower crushing-conveyer.

In test imony whereof I affix my signature in presence of two witnesses.

, TIIOS. ROBERTS.

Vitnesses:

B. O. CONVERSE, A. E. ALDRICH.

